Category: Testing Techniques


My Patchwork tile is complete but hasn’t turned out quite as I’d hoped…

I cooked it on a glassfire automatic program, full fuse on medium but it didn’t fuse completely.

Tile after full fuse

Tile after full fuse

As you can see, there are little gaps at the corner of the green squares, dark lines around the turquoise square and the two tiles  at the top and bottom are not quite fused.

So in it went again.

This time I went for the full fuse, slow cook and its looking quite a bit better. There are still a few tiny gaps and it’s not perfect in every way, but it’s fun.

Patchwork tile after second fusing

Patchwork tile after second fusing

As you may remember from my last post, this was a flip and fire exercise so, as it went in with the design layer on the bottom the first time, I turned it over for the second firing so the design layer was on the top.

I don’t think this is a piece to sell but it looks a treat on my studio window ledge with the snow behind it!

 

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Having learnt my lesson about compatible glass I have put together two trivet-sized pieces. Several days out of the kiln, they are still crack-free and providing quite a boost to my glass education.

The first, a conglomeration of scrap and sample pieces of opaque glass and clear bullseye tekta has, I think, quite an Art Deco feel about it.

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Those of you with some experience in fusing will recognize my mistake in placing two of the red squares in the ‘accent’ layer too close to the corners. As well as distorting the piece into an elongated diamond rather than a square, they also appear to have run over the edge rather than staying on top.

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Rather than seeing this as a fault, my other half quite liked the quirky, handmade look this conveyed. I can live with that…
The second piece was more technically successful.

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This was formed from two layers of clear tekta glass with copper sheet strips sandwiched in between. The coloured squares were cut slightly smaller than the clear windows in between the copper and laid on top.
I like this piece best although the copper has stopped the glass flowing as fluently as it has in the spaces in between giving it the looked of a tied parcel! I like the dark red/purple colour the copper has turned.
Both pieces were fired on a slow, full fuse auto program but I wonder if a medium program would produce less distortion?

Getting Cracking

Since my last post things have moved on apace as, nervous that my all-wood and frankly freezing studio wouldn’t fare well over the winter, I have moved the whole show back to a studio in the nearby Brickworks Museum.

I say back, as this is where I used to run my sewing workshops, but now something new.

After my last post in which my sample piece – made despite advice to the contrary – of different grades of glass – cracked 48 hours after firing, I had a few more attempts with the gifted glass and bullseye glass. All have cracked to some degree.

You would think by now that I’d have learnt my lesson. But, having put together these Christmas ornaments, I just had to try the addition of some millefiore  pieces, bought when I went on a mosaic course. Christmas decoration for the trees, I thought, and sprinkled them liberally.

Here are the pieces just before firing.

Ready to Fire

Ready to Fire

I am always excited when it’s time to open the kiln. Firing and cooling takes such a long time and the result is so different each time that I can’t wait to see what’s happened.

I was pleased and disappointed at the same time.

Round hanging ornament

Round hanging ornament

Doesn’t look too bad but on closer inspection there is quite severe cracking around one of the millefiore which is also a little too close to its neighbour.

Cracking Detail

Cracking Detail

The two tree shaped ornaments fared rather better but there is still a little bit of cracking around the inclusions.

I was interested to see how the yellow one had bulged into a bottle shape. I think this is either due to too large a piece of glass on top or overcooking!

red tree ornament

yello green tree ornament

I also like the way the milliefiore have shifted in the molten glass creating the sort of effect you get with adverts on football pitches.

But despite the cracking, these pieces were only intended as extra Christmas decorations and are still usable, I think. Also, my lovely glass suppliers sell milliefiore that is compatible with Bullseye glass so guess where I’m going next?

I think the lesson is learned though. No more incompatible glass experiments!

I’ve got two new (compatible) pieces in the kiln at the moment so watch this space!

The First Step

Kilns are expensive. I hadn’t realised quite how expensive until I looked into buying one.

But, as I only want to work with glass, I don’t need something as big and powerful as is required for ceramics, and have settled on a specialist glass kiln. Small, compact, but quite big enough for my intentions for the foreseeable future. I was concerned that something that gets as hot as a kiln may be a step too far for my all-wood workshop. But I was assured, by the aptly-named and very helpful Warm Glass Company of Bristol, that it would be fine as the exterior of the kiln doesn’t get much hotter than a radiator.

 

My Skutt Firebox 14

My Skutt Firebox 14

I was tremendously excited when the kiln arrived, packed up in an enormous box all the way from Portland, Oregon. It took some time and effort and the help of my long-suffering partner, to get it out of the box (which wouldn’t fit through the door) and into my studio.

It lay in the middle of the floor for a few days, until I got some ceramic floor tiles to sit it on and until the rest of my tools arrived.

My Kristall Glass Grinder

My Kristall Glass Grinder

Once it was installed on the metal stand and was all ready to go, I suddenly became a little nervous of it and wasted another few days shilly-shallying around and being busy with other things.

I had been given a large quantity of art glass by a local community outfit who are hoping I might be up to doing some workshops for them next year and, having selected a sheet of what looked like 3mm thickness, I decided to give it a go.

I have always found glass-cutting a bit of a dark art in the past, but after taking Brad Walker’s advice in his ‘Contemporary Fused Glass’, I bought a medium-range oil-filled cutter and am surprised how easy it is – once you have the right tools!

I have read a lot about using compatible glass (which has the same COE – Coefficient of  expansion) in the various library books I’ve got (and the Brad Walker book) but as I had no idea of the COE of the gifted glass, I just had to give it a try.

I had also bought a student pack of Bullseye glass offcuts, which I am reliably informed has a COE of 90.

I cut a 5″ square from the glass that I’d been given and cut a few vaguely Christmas tree shapes from one of the green Bullseye glass pieces. I laid the green shapes on the clear glass and, after lining the kiln shelf with the Thinfire paper which came with the kiln, I placed the tile on the shelf and was ready to go.

The beauty of my new kiln is that it comes pre-programmed with a number of automatic programmes which allow beginners to get going without having to write their own firing schedules. All I had to decide was if I wanted a Fast, Medium or slow heating rate which depended on the thickness and size of my piece. Impatiently, but rightly, it turns out, I went for Fast! I also had to choose from Full fuse, tac or slump. That was of course Full fuse.

When the kiln started, about 3:15pm and for the next few hours, I kept to the far end of my workshop (which is 30 feet long) and fretted about things going wrong.

I had assumed that Fast meant my piece would be ready quickly, but seven hours later, the kiln was still showing a toasty 200 degrees C (even though the programme had declared itself complete after about 6 hours) so I decided to switch it off  and save the pleasure of seeing my first attempt until the next morning.

And here it is.

first sample piece

 

Now you may notice the little crack on the top left hand side. That wasn’t there when I first opened the kiln and didn’t appear until 48 hours later! So at first glance I was delighted and declared to anyone who would listen that it had been a success and about all the things I was going to make with my gifted glass.

I had of course read that this was likely to happen with untested glass and cracks could appear on firing or even months or years later! I don’t know if it may also be because I only used one layer of glass and an accent layer. If I had read the books more fully before I got started, I would have realised that ‘glass needs two layers’ and I should have used a base layer, a design layer and an accent layer.

The impatience of beginners!

incompatibility crack

I was a little disappointed when the crack appeared as it means I’m going to have to buy some compatible clear glass for my planned projects. But I have plans for the gifted glass and I hope to share these with you in my next post.